The present invention relates to a recording medium library device which houses a plurality of recording media loadable/unloadable to/from a recording and reproducing apparatus, such as cassette tapes, and is capable of recording/reproducing various information to/from the housed recording medium as necessary. The present invention also relates to methods of setting occupancy, determining and notifying completion of loading a recording medium, and cleaning for such a recording medium library device.
There has long been a system which houses a plurality of recording media (cassette tapes or disk-shaped recording media, for example) loadable/unloadable to/from a recording and reproducing apparatus and records various information onto the housed recording media and reproduces the recorded information as necessary. Such a system is called a library system, auto-changer, or the like. In the following description, it will be called a library system.
Some library systems have predetermined compositions. Other library systems have compositions which can be adapted to a certain degree to suit the user. An example of the latter library systems has a plurality of consoles. The consoles are combined freely to form library systems of various sizes and arrangements. Examples of the consoles are a drive console and a console for housing recording media. A drive console has a recording and reproducing apparatus which records and reproduces information onto/from a recording medium. A console for housing recording media has a plurality of housing sections, each capable of housing a recording medium. Some consoles for recording and reproduction further comprise a plurality of housing sections, each capable of housing a recording medium. Moreover, the latter library system comprises a carrier apparatus and a control unit. The carrier apparatus carries a recording medium between any one of the housing sections and the recording and reproducing apparatus. The control unit controls the recording and reproducing apparatus and the carrier apparatus.
In the library system, under the control of the control unit, the carrying apparatus is controlled to carry a recording medium between any one of the housing sections and the recording and reproducing apparatus. Various information is recorded on the recording medium carried to the recording and reproducing apparatus, and the recorded information is reproduced.
Such a library system has some problems as described hereinbelow.
The first problem is as follows.
Some library systems are connected to one or more host computers serving as client(s) so that the host computer can use the library systems. In this case, a library system is connected to the host computer by, for example, a transmission line of the standard for jukebox in the SCSI (Small Computer System Interface) standard established by ANSI (American National Standards Institute).
In cases, as for example where one library system is shared by a plurality of host computers, a control unit of the library system may set occupancy of a plurality of recording and reproducing apparatuses, housing sections and the like for each host computer as a client. The occupancy is set through giving continuous address numbers to the recording and reproducing apparatuses and allocating the address numbers to each host computer. By the operation, each host computer can use only the occupied recording and reproducing apparatus and the like. At this time, it is necessary to allocate continuous address numbers to one host computer because of the standard of the transmission line used to connect the host computer to the library system.
Conventionally, the only method of setting occupancy is therefore to allocate physically continuous recording and reproducing apparatuses or the like to one host computer. An arbitrary address number cannot be allocated to one host computer. This results in a problem of the low degree of freedom in setting occupancy. For example, when one of the physically continuous recording and reproducing apparatuses fails, the address numbers are interrupted. This causes a problem that, in the host computer occupying the failed recording and reproducing apparatus, a process of changing the occupancy setting so as to occupy a recording and reproducing apparatus for replacement cannot be performed.
The second problem is as follows.
In a library system having the composition as mentioned above, when a recording medium is carried by the carrying apparatus from the console for housing recording media and loaded to the recording and reproducing apparatus, the recording and reproducing apparatus performs a preparing operation for reading predetermined retrieval information from the loaded recording medium. The retrieval information, which is read by the preparing operation, includes information on, for example, an address on the recording medium of data recorded on the recording medium. By reading the retrieval information in advance, the processing speed with which data on the recording medium is accessed in response to a reproduction request from an upper control computer can be increased. This speed-up contributes to the improvement of the processing efficiency of the library system as a whole.
In this case, after the preparing operation is finished, the recording and reproducing apparatus notifies the upper control computer of completion of carriage of the recording medium. When the upper control computer receives the notification, the upper control computer issues the next recording medium carrying command to the library system.
The preparing operation requires, however, a relatively long time of 30 seconds to one minute. During the period, the upper control computer remains waiting for the notification from the recording and reproducing apparatus of completion of carriage of the recording medium. The carrying apparatus of the library system therefore also remains waiting. This waiting period becomes a useless time, causing a problem of deterioration in the processing efficiency of the library system as a whole.
The third problem is as follows.
In a library system having the above-described composition, a number of recording media are used. In order to maintain always the high recording and reproduction quality, it is necessary to clean the recording and reproducing head of the recording and reproducing apparatus periodically or as necessary. Conventionally, a cleaning medium is housed in part of the console for housing recording media. With manual operation by the user, periodically or as necessary, the cleaning medium is carried from the console for housing recording media to each recording and reproducing apparatus to clean the head.
As described above, cleaning the head of the recording and reproducing apparatus by manual operation is time-consuming. Also, it is not easy to manage timely head cleaning of each recording and reproducing apparatus without missing the timing of head cleaning. As a result, the operating cost of the system is high and it is difficult to properly control the system operation. A possible way to deal with the problem is to perform automatically and periodically the head cleaning process of each recording and reproducing apparatus by using a cleaning medium housed in the console for housing recording media.
When the recording medium used in the library system as described above is in a tape form such as a video cassette tape, the cleaning medium used for cleaning the recording and reproducing apparatus is also in a tape form. That is, a cleaning cassette is used. Some cleaning cassettes cannot be rewound and used repeatedly and are to be disposed when the tape is used up. In order to ensure cleaning by using such a cleaning cassette, it is indispensable that a usable tape area is left in the cleaning cassette.
In cases where head cleaning is performed by manual operation, it is possible to keep track of the amount of the usable tape area of the cleaning cassette accurately by checking the number of times each cleaning cassette is used. If the number of times a cleaning cassette is used reaches a specified number, the cleaning cassette can be taken out from the cassette housing shelf and disposed.
On the other hand, in the cases of automatic head cleaning as mentioned above, the user can no longer keep track of the number of times a cleaning cassette is used. Consequently, a cleaning cassette whose tape has been ended or a cleaning tape having an insufficient remaining amount may be used for the head cleaning process. It is also expected that the head cleaning is not performed at all or not performed sufficiently in practice. In order to prevent this, with each head cleaning process, the user has to unload the cleaning cassette used for the head cleaning from a cassette housing shelf, visually check the remaining amount of the tape, and determine whether the head cleaning has been performed properly or failed since the tape is ended. This makes the automatization of the head cleaning process meaningless.
The invention has been achieved in consideration of the above problems. It is an object of the invention to provide a recording medium library device capable of freely setting occupancy for a client and a method of setting occupancy.
Another object of the invention is to provide a recording medium library device capable of improving the efficiency of the whole system by eliminating useless waiting time related to carriage of a recording medium, and a method for determining completion of loading a recording medium, and a method for notifying completion of loading a recording medium.
Still another object of the invention is to provide a recording medium library device which enables proper management of use of a cleaning medium housed in a console for housing a recording medium so as to ensure cleaning, and to provide a cleaning method.
A recording medium library device according to the invention comprises: one or more recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means in response to a request from a client, wherein the control means has a function of setting a part to be occupied for one or more clients and a function of converting between a physical address and a logical address managed by the client, with respect to a part to be occupied. In the recording medium library device, conversion between a physical address and a logical address managed by a client is performed and a part to be occupied is set for one or more client(s) by the control means.
An occupancy setting method according to the invention is a method of setting a part to be occupied for each client in a recording medium library device which comprises: one or more recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means in response to a request from a client, wherein the control means sets a part to be occupied for one or more client(s) and converts between a physical address and a logical address managed by the client, with respect to a part to be occupied. In the occupancy setting method for the recording medium library device, in the control means, conversion between a physical address and a logical address managed by the client is performed and a part to be occupied is set for one or more client(s).
Another recording medium library device according to the invention comprises: recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; detecting means for detecting carriage of the recording medium by the carrying means to the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means, the control means having the function of sending a request to load the recording medium housed in the housing section in the recording medium housing means into the recording and reproducing means to the carrying means, and when the detecting means detects the carriage of the recording medium to the recording and reproducing means, determining that the loading of the recording medium has been completed, without waiting for completion of a preparing operation in the recording and reproducing means after the recording medium has been loaded. The control means can be constructed to send a request to load the recording medium housed in the housing section in the recording medium housing means into the recording and reproducing means in response to a request from the client and, when it is determined that the loading of the recording medium into the recording and reproducing means has been completed, to send a notification of the recording media loading completion to the client.
According to the invention, there is provided a method of determining completion of loading of a recording medium in a recording medium library device which comprises: recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; detecting means for detecting carriage of the recording medium by the carrying means to the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means, wherein the control means sends to the carrying means a request to load the recording medium housed in the housing section in the recording medium housing means to the recording and reproducing means and, when the detecting means detects the carriage of the recording medium to the recording and reproducing means, determines that the loading of the recording medium has been completed, without waiting for completion of a preparing operation in the recording and reproducing means after the recording medium has been loaded.
According to the invention, there is provided a method of notifying a client of completion of loading of a recording medium in a recording medium library device which comprises: recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; detecting means for detecting carriage of the recording medium to the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means in response to a request from a client, wherein in the control means, when a request to load the recording medium housed in the housing section in the recording medium housing means into the recording and reproducing means is received from the client and the carriage of the recording medium is detected by the detecting means, it is determined that the loading of the recording medium has been completed, without waiting for completion of the preparing operation in the recording and reproducing means after the recording medium is loaded and the completion of loading of the recording medium is notified to the client.
In the recording medium library device or the method of determining completion of loading of a recording medium for the device of the invention, the request to load the recording medium housed in the housing section in the recording medium housing means to the recording and reproducing means is sent to the carrying means. When the carriage of the recording medium to the recording and reproducing medium is detected by the detecting means, it is determined that the loading of the recording medium has been completed, without waiting for completion of the preparing operation to be executed by the recording and reproducing means after the recording medium is loaded.
In a method of notifying completion of loading of a recording media for a recording medium library device according to the invention, in response to a request from the client, a request to load the recording medium housed in the housing section in the recording medium housing means to the recording and reproducing means is sent to the carrying means. When the carriage of the recording medium to the recording and reproducing means is detected by the detecting means, it is determined that the loading of the recording medium has been completed, without waiting for completion of the preparing operation to be executed by the recording and reproducing means after the recording medium is loaded, and the client is notified of the completion of loading of the recording medium.
Still another recording medium library device of the invention comprises: recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means, wherein the control means has an automatic cleaning function of controlling the carrying means and the recording and reproducing means to automatically carry, at a preset timing, a cleaning medium used for cleaning the recording and reproducing means from the housing section in the recording medium housing means to the recording and reproducing means, to allow the cleaning medium to clean the recording and reproducing means, and then to carry the cleaning medium to the housing section in the recording medium housing means, and a function of monitoring a state of use of the cleaning medium and determining whether the cleaning medium has been used to its limit or not. When the number of times the cleaning medium is used reaches a predetermined number or when there is no usable area of the cleaning medium, the control means can determine that the cleaning medium has been used to its limit. In addition to the above configuration, the recording medium library device can further comprise an ejecting unit for ejecting the recording medium and the cleaning medium to the outside, and the cleaning medium can be carried to the ejecting unit when it is determined that the cleaning medium has been used to its limit. The control means may be also configured to output information to eject the cleaning medium when it is determined that the cleaning medium has been used to its limit.
According to a cleaning method of a recording medium library device of the invention comprising: recording and reproducing means for performing at least either recording or reproduction of information by using a removable recording medium; recording medium housing means having a plurality of housing sections, each capable of housing the recording medium; carrying means for carrying the recording medium between any one of the housing sections in the recording medium housing means and the recording and reproducing means; and control means for controlling the carrying means and the recording and reproducing means, the control means controls the carrying means and the recording and reproducing means to automatically carry, at a preset timing, a cleaning medium used for cleaning the recording and reproducing means from the housing section in the recording medium housing means to the recording and reproducing means, to allow the cleaning medium to clean the recording and reproducing means, after that, to carry the cleaning medium to the housing section in the recording medium housing means, while monitoring the state of use of the cleaning medium and determining whether the cleaning medium has been used to its limit or not.
In still another recording medium library device or a cleaning method thereof according to the invention, the cleaning medium is automatically carried from the housing section in the recording medium housing means to the recording and reproducing means at a preset timing. The recording and reproducing means is cleaned by the cleaning medium. After that, the cleaning medium is carried to the housing section in the recording medium housing means. The state of use of the cleaning medium is monitored and it is determined whether the cleaning medium has been used to its limit or not.
Other objects, features and advantages of the invention will appear more fully from the following description.